Noise at Work on Construction Sites: The 80, 85 and 87 dB Rules

Pro Site Docs · Guide

Noise damage is gradual, painless and permanent, and on a construction site it comes from a handful of tasks that take minutes rather than hours. The regulations set three thresholds. Most sites cross the top one before the tea break.

The three thresholds

The Control of Noise at Work Regulations 2005 set a lower exposure action value of 80 dB(A), an upper exposure action value of 85 dB(A), and an exposure limit value of 87 dB(A), all as daily (or weekly) personal exposure. There are matching peak values of 135, 137 and 140 dB(C) for impulsive noise - cartridge tools, nail guns, dropped steel. The limit value is the only one that takes hearing protection into account: it is the level at the ear.

How daily exposure adds up

Decibels are logarithmic, so every 3 dB doubles the sound energy and halves the time allowed for the same dose. Daily exposure, L_EP,d, combines each task's level and duration into the equivalent constant level over eight hours. At 110 dB(A) - a disc cutter or scabbler - the 85 dB upper action value is reached in under five minutes. At 100 dB(A) it is about fifteen minutes; at 90 dB(A), about two and a half hours. The noise exposure calculator runs the sum for a day's tasks.

What you must do at each level

At 80 dB(A): assess the risk, make hearing protection available to anyone who asks, and provide information and training. At 85 dB(A): reduce exposure by means other than hearing protection so far as reasonably practicable, mark hearing protection zones, make sure protection is worn, and provide health surveillance (audiometry). At 87 dB(A) at the ear: must not be exceeded - if it is, act immediately to bring it down.

Reducing noise at source

Hearing protection is last in the hierarchy, not first. Quieter methods (breaking with a hydraulic bursting tool instead of a breaker; cutting blocks with a bench saw and water rather than a disc cutter), quieter equipment (buy on the declared noise figure), maintenance (blunt blades are louder), distance and screens for the people not doing the task, and limiting time by rotating the job. Most of these also cut dust and vibration.

Choosing hearing protection

Protection is rated by SNR. Subtract roughly the SNR minus 4 (the HSE's real-world allowance) from the task level to get what reaches the ear. A foam plug at SNR 30 is fine on a breaker; on general site noise in the low 80s it over-protects and isolates people from reversing alarms and shouted warnings. For mixed work, a lower-SNR protector or a fit-tested plug is usually the better choice. The assessment should name the protector for the task, not 'hearing protection to be worn'.

Health surveillance

Required for anyone regularly exposed above the upper action value: a baseline hearing test, then regular audiometry, through an occupational health provider. Keep the records. As with HAVS, the disease appears years after the exposure and the claims follow it.

Get the documents ready-made

Put it in writing with a noise risk assessment and a hearing protection register. The occupational health templates include both, and the Toolbox Talks Library has the noise talk ready to deliver.

General guidance only. This article explains how the rules generally work in UK construction. It is not advice for your specific site, task or project, and it is not legal advice. Your own risk assessment, method statement and arrangements must be prepared and checked by a competent person for the actual work being done.